Signaling device



Jan; 20, 193-1. T. J. SCOFIELD ETAL S IGNALING DEVICE Filed Dec. 22, 1924 3 Sheets-Sheet 1 .lllll Jan. 20, 1931. 1-. J. SCOFIELD ET AL 1,739,947

SIGNALING DEVICE Filed Dec. 22, 1924 s Sheets-Sheet 2 AM- I wing:-

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3 Sheets-Sheet 3 SIGNALING DEVICE Filed Dec. 22, 1924 ToR 5Y5 Patented Jan. 20, 1931.

UNITED STATES THEODORE J. SGOFIELD AND LLOYD E. JOHNSON, OF JACKSON, MICHIGAN, ASSIGNORS PATENT OFFICE TO THE SPARKS-WITHINGTON COMPANY, OF JACKSON, MICHIGAN, A CORPORATION OF OHIO SIGNALING DEVICE Application filed December 22, 1924. Serial No. 757,424.

This invention relates to a certain new and improved signaling device, and more' particularly to a signaling device or horn of the magnetically actuated type.

The main object of the invention is the production of an eflicient signaling device of substantial construction, and of economic manufacture and arrangement, and which will produce a signal of the desired character pitch and amplitude.

Other objects and advantages relate to the details of the structure and the form, position, arrangement and association of the parts thereof, all as will more fully appear from the following description, taken in connection with the accompanying drawings, in which Figure 1 is a top plan view of a signaling device of this invention.

Figure 2 is a longitudinal section on line 22, Figure 1.

Figure 3 is a diagrammatic illustration of suitable electrical circuits for operating the device.

Figure 4 is a longitudinal sectional view taken at right angles to Figure 2.

Figure 5 is a section on line 55, Figure 1.

Figure 6 is a section on line 66, Figure 1.

Figure 7 is an enlarged view of certain portions of the structure as illustrated in Figure 4.

Figure 8 is a perspective view of the magnet or magnetic field.

Figure 9 is a view of the clip used for attaching the enclosing casing to the signaling structure, and for maintaining the field coil in proper position.

Figures 10, 11 and 12 are perspective views of the yoke spring and washer and the interlocking means for said parts when assembled.

Figure 13 is an end view of the bushing or sleeve upon which the diaphragm is threaded and with the resonator mounted thereon.

The structure of signaling device here illustrated is of the magnetically operated diaphragm type, and as shown, comprises a pressed metal rear diaphragm case-section 1 having its central portion dished and of substantially cylindrical cup-shape, and

formed at its central portion with an openv the front diaphragm case section 4, the

ring or washer 6 being preferably interposed between the edge of the diaphragm and the front case-section 4, with bolts 5 extending through the diaphragm case sections, the diaphragm and the ring, and provided with nuts 7 for tightly and rigidly clamping all of these parts together. The front diaphragm case-section 4 may, as shown, carry an elongated resonator 8. The magnet or magnetic field -2 is preferably of the form best illustrated in Figure 8 and may be built up of similarly formed thin strips of metal secured together by transversely extending rivets 9.

The side sections of this magnet areformed with laterally extending perforated cars 10- which, when the magnet is placed in the opening at the rear diaphragm case section 1,. project outwardly along the rear surface of the said case-section, and are secured thereto in any suitable manner, as by rivets 11, so that in effect the magnetic field becomes a unitary rigid part of the rear diaphragm case-section -1.

As illustrated, the magnet 2 is formed with a central substantially rectangular boss 12 which extends throughout the width of the magnet, but is separated from the op posite ends of themagnet by lateral grooves or channels within which channels the laterally-extending portions of a field coil 13 are positioned in the assembled structure. This field coil in a well-known manner is built up of coiled wire, and is externally taped so as to insulate it from the magnet 2, and as perhaps best illustrated in Figures 4 and 7, lies wholly forward of the rear surface bordering the central opening. A sleeve -15- is provided with an externally threaded portion for coaction with the inlet threaded collar 14 whichconstitutes a rigid portion with the diaphragm, and one end of the sleeve projects forwardly from the diaphragm and is flatted upon diametrically opposite sides for the reception of a plate or disk 16- which has a non-circular, in the illustration a somewhat oval-shaped opening adapted to fit the end of sleeve 15 so that the disk can be used to rotate the sleeve, and the disk is secured in position upon the end of the sleeve by means of headed bolt 17 and clamped against bushing -14 in the center of the diaphragm, the head of, the bolt being preferably separated from the disk 16- by means of washer 18. The bolt -17 extends entirely through the sleeve 15 and projects from the rear portion thereof, and passes through the armature 19, washer 20, leaf-spring '21, and is threaded into the flat base 22 of a yoke 23 which rests upon the upper surface of the spring 21.

For the purpose of effecting a rigid and tight engagement between the diaphragm 3, disk 16-, sleeve 15, bolt 17, armature 19-, washer 20-, spring 21- and yoke 23, the rear end of sleeve 15- is somewhat enlarged and spherically shaped so as to seat tightly in a substantially I similarly spherically shaped recess in the adjacent side of the armature -19, and the opposite side of the armature is formed with a flat recess of circular form for the reception of washer 20-.

Washer 26- is provided with a substantially spherical seat for contact with the rear curved or spherical portion of the washer 20, such washer 26 being interposed between the spring 21 and the washer 20 and having recesses 2T for the reception of the lugs 24 formed on yoke -2? and which extend through recesses 28 in the spring 21-, but do not contact with the rear spherical surface of Washer 20.

It will be obvious that by turning the bolt 17- so as to thread it into yoke 23, the parts named will be rigidly secured together for unitary movement, the leaf spring 2l having its opposite end tightly secured, as

hereinafter described, constituting an aligning means for the yoke and the washer 26 by reason of the fact thatthe lugs 24 project through the recesses 28 in the spring, and are positioned in the recesses 27 in the washer -26. The armature is arranged in this construction so as to be formly at substantially all points when drawn into contact therewith upon energizing the field magnet by current 'flowing through the coil -13.

An automatic circuit breaker is provided, as is usual in horns of this type, whereby the field coil is automatically energized intermittently. A built-up pedestal is provided at the rear of and carried by the diaphragm case-section -1-- and this for the purpose of carrying the contacts which are intermittently separated and brought together, as hereinafter described.

This pedestal, as shown, consists of a series of similarly shaped metallic blocks. For illustration, a block 29 rests against the rear face of the case-section -1 at one side of the openingin the case-section, and of the magnet -2. One end of the spring 21 rests upon the outer surface of this block 29- and a second block 30 of similar form rests upon the outer surface of the spring 21-. An insulating strip 31 is then placed upon the outer surface of the block -30 and the end of a spring-bar --32- is placed upon the outer surface of this insulating plate 21. A second insulatingdisk 33 is placed upon the outer surface of the flexible bar -32- and the end of a rigid bar 34 is placed upon the outer surface of this insulating disk 33. Another insulating disk 35 is placed on the outer surface of the rigid bar 34 and a block -36 rests upon the outer surface of this insulating-plate and all of the parts described as constituting the pedestal, are formed with a plurality, in this instance three openings aligned in the assembled structure for the reception of the three screws 57 the heads of which rest against the block 36 and the inner ends of which are threaded into properly interiorly threaded openings in the diaphragm case section 1, to thereby form a rigid pedestal.

The flexible arm 32 carries one contact 37 while the offset end of the rigid arm 34 carries the other contact -38, the latter-contact being mounted upon the end of a screw threaded through the rigid bar 34 to permit its adjustability as desired.

For the purpose of insulating the flexible arm 32 and the rigid arm 34 from the screws 57, the insulating disk 31- is formed with three upstanding cylindrical bosses 62 surrounding respective screws and spacing and insulating said arms from the screws.

The flexible arm extends beyond the contact 37 and into the central space in the yoke 23 and is provided at its end with a cup-shaped member 39 containing any suitable hard insulating contact material -40 for contact with the adjustable screw -41 carried by the yoke 23, as illustrated.

suitable circuit-closer The 0' posite end of the spring 21- is secured etween a block 51 and plate -52-, the blocks and the spring belng secured to the diaphragm case-section 1 by means of screws 43.

As diagrammatically illustrated in Figure 3, a condenser 42 is shunted across the contacts -37- and -38 and is perhaps best illustrated in Figures 4 and 6. This condenser is here shown as of cylindrical form, and is contained in the dished portion of the diaphragm case section 1, and is held in such position against the diaphra m case-section, and the field ma net 2 by curved spring 63 aving one end secured to the field magnetby screw -44 and its opposite end curved about the c lindrical condenser to maintain it in desire position. This condenser tends to prevent arcing between the points 37 and -38- as contact is being made and broken. I

The operation of the structure will be well understood.

' As the circuit is closed by means of any or switch, current will flow through the field coil -13-, energize the field magnet 2 and the armature 19 will be drawn into contact with the field magnet taking along with it spring -21- and yoke 23-.

Movement of the yoke -23 by contact of adjustable screw 4=1- with the cup --40- will depress the flexible arm 32, and separate the contacts -37 and 38- whereby the circuit will be broken, whereupon the armature 19, will be returned to normal position by operation of the spring -20 and the diaphragm -3. Upon its return the spring-arm 32 will likewise move to normal position bringin contact 37- against contact 38 whereiy the circuit will again be completed, and again the armature 19- will be drawn into contact With the magnet. During this operation, vibration of the diaphragm 3 and plate --16 will be effected.

A casing of cup sha e cap is provided for enclosing t e magnet, armature contacts and other operative arts at the rear of the diaphragm case sect1on 1-, and novel means is provided for maintaining this casing in desired position in the form of studs projecting inwardly from diametricallyopposite portions of the casing -70 and adapted to pass between two opposed s ring portions of clips 72- having their at bases secured to the rear diaphragm case section -1 in any suitable manner, as by means of rivets.

These clips, as perhaps best illustrated in Figure 9, may be formed of a single strip of spring metal as steel, and in the structure of the horn have two functions. The flan es ent' upwardly and 1nwardly from the base and then turned outmeans of tating the disk -16-, the through the diaphragm and adjustment efwardly as illustrated, constitute jaws for gripping the inwardly extending studs -71- in a flexible manner to maintain the case 70 in tight relation with respect to the case-section -1. End pieces are rovided with laterally extending flan es 6- which, as shown, extend above an partially across the field coil -13 when positioned .111 the magnet 2- and maintain the field coil in its position in the grooves formed in the magnet. In order to assemble the case with the other portion of the, structure, it is only necessary to aline the studs with the opening between the diverging ends of the jaws 73 and 74 to ress the case inwardly until the studs pass by the contracted portion of the jaws when the case will be maintained in desired position. To remove the case, it is only necessary to apply sulficient power to withdraw the-studs past the contracted portions of the jaws.

It is of extreme importance in this horn that the armature be adjusted the proper distance from the field, and the clearance is slight, and this adjustment can be effected and maintained in the present structure with great ease and efficiency in that the sleeve 15 against which the armature rests is threaded through the diaphragm, and by revolving the sleeve 15 the armature 19 is moved nearer to or farther from the field, permitting very accurate relationship, and as the sleeve has two flat sides mounted on the end to receive the resonator which has a non-circular opening to fit the end of, the sleeve by merely rosleeve is screwed fected, and the parts can then be'locked together by tightening screw --17 Altho we have shown and described a specific structure and particular details of form and arrangement of the parts thereof as constituting a perhaps preferred embodiment of our invention, we do not desire to restrict ourselves to the details of form, construction or arrangement, as various changes may be made wlthin the scope of the appended claims.

We claim:

1. .In a signal, a sheet metal rear diaphragm case section having a substantially central opening, a magnet core secured in the ,opening and having grooves, a coil seated in said rooves, a clip secured to the case-section and aving aflan e extending across the adjacent portion 0 the coil to maintain the same in thegroove in the magnet core, said clip having a pair of inwardly inclined spring, jaws pro ecting outwardly from the case-section, and a cup-shape cap having an inwardly projecting stud engaged by said jaws to maintain the cap in proper relation with respect to the case section.

2. A signal comprising a rear diaphragm case-section formed of sheet metal, a diaphragm having a central opening, means for securing the diaphragm to the case-section, a sleeve threaded into the central opening in the diaphragm and having a part extending forwardly from the diaphragm and formed with opposite flat sides, an armature on the other end of the sleeve, a disk mounted on the forward extending portion of the sleeve and having an opening adapted to fit the flattened portion thereof whereby rotary movement of the disk will cause rotary movement of the sleeve, and means for securing the disk and the sleeve in fixed relation to the diaphragm.

3. A signal comprising a rear diaphragm case section, a diaphragm having a central opening, means for securing the diaphragm to the case section, a sleeve threaded into the central opening in the diaphragm and having a part extending forwardly from the diaphragm, such part being of an out of round form, an armature on the other end of the sleeve, a disk mounted on the forward extending portion of the sleeve and having an opening adapted to fit the out-of-round portion whereby rotary movement of the disk will cause rotary movement of the sleeve, and means for securing the disk and the sleeve in fixed relation to the diaphragm.

39 4. In a signal, a sheet metal rear diaphragm case section having a substantially central opening, a magnet core secured in the opening and having grooves, a coil seated in said grooves, a sheet metal member secured to the case section having a portion extending over a part of the coil to hold the latter in the magnet groove and another portion bent to form a latching member and a cupshaped cap having an inwardly projecting ijtud for engagement with the latching mem- In witness whereof we have hereunto set our hands this 12th day of December, 1924.

THEODORE J SCOFIELD. 5 LLOYD E. JOHNSON. 

